package project3.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention (RetentionPolicy.RUNTIME)
public @interface Constrain {
	// 约束
	boolean NotNull() default false;
	boolean PrimaryKey() default false;
	boolean Unique() default false;
}
